Identification of a Novel HIV-1 Circulating Recombinant Form (CRF184_BC) Among Heterosexual Populations Along the China-Myanmar Border Region.

The China-Myanmar border region is recognized as a hotspot for the emergence of HIV-1 recombinant forms. This study identified a novel HIV-1 circulating recombinant form (CRF) in this area, designated CRF184_BC. Near-full-length genome sequences were obtained from four individuals infected through heterosexual contact: one Chinese individual and three Burmese individuals. These sequences formed a distinct monophyletic clade with strong bootstrap support, separate from all known subtypes/CRFs. Recombination analysis revealed a conserved mosaic structure comprising four subtype C segments and three subtype B segments: IC (790-2897), IIB (2898-3208), IIIC (3209-5983), IVB (5984-6435), VC (6436-8821), VIB (8822-8969), and VIIC (8970-9468). Bayesian Markov chain Monte Carlo analysis indicated that CRF184_BC emerged between the mid-2000s and the early 2010s. Identifying emerging CRFs highlights the ongoing dynamic evolution of HIV-1 in this region and emphasizes the need for enhanced molecular surveillance to inform effective public health strategies and vaccine development efforts.